Various motion devices have been provided utilizing complicated cams and followers or a system of links to provide an accelerating and decelerating motion for transferring workpieces. Many of these motion devices are used for reciprocating a member, such as a multiple indexing table along a straight path and provide a smooth starting and stopping motion to reduce shock.
Many applications arise in which it is required to transfer workpieces from one location to another. For example, one method of transferring workpieces is known as free part transfer. In this method, a workpiece, such as a cam shaft, is independently transferred from one location to another. This method utilizes a transfer device that clamps a workpiece at a first location, lifts and carries the workpiece to another location, and then releases the workpiece. Another method of transfer may use a rotary or reciprocating index table. It is often desirable to move the workpiece through an accelerating and decelerating motion in which the workpiece is first slowly accelerated to a peak velocity, decelerated, and deposited in another location.
While various drive mechanisms have been used for these applications, it is still desirable to provide a drive mechanism which has a faster cycle time but which more gently moves through its accelerated and decelerated motion.